One thing leads to another.
If you both enjoy your first date, chances are you'll have a second date. Dates get repeated for a while. You visit his place....he visits yours. He meets your friends...you meet his. You find out about each other's lives.
Pretty soon, you get a fairly good 360 degree view of each other. The sex is good and getting even better. You think of him all the time. All good.
But pay attention to his negatives...red flags like drugs, closeted, selfishness, obnoxious friends, inability to keep commitments, etc. They are easy to hide or minimize in the first few months. Everybody has negatives...you just need to ask yourself what you think his are, and if you can live with them in the long term.
Ask yourself what's important to YOU. If you make 25 grand a year, and he has expensive tastes, you need to sit down and have a discussion about money and lifestyle. Otherwise, you're going to wind up in debt, and he'll eventually conclude things aren't working for him either. Be honest. If he really likes you, he'll learn to bank his extra money and enjoy cheap dates. It's called COMMUNICATION and COMPROMISE. All good relationships have it.
Which points to the ultimate reason for a relationship...LOVE. Your love for each other should trump everything else in the world. Family. Jobs. Friends. Material possessions. Doesn't mean everything else is ignored...but you will know in your heart how important you are to each other. It takes a long time to fully know each other. I know a couple who have been together for 43 years...they say that it takes a good 10 years before you really know somebody. If all works out, you'll eventually consider each other...a FAMILY.